Better ability to handle per-dsl-method defaults

spec/args/draw_spec.rb

@@ -15,6 +15,16 @@ describe Squib::Args::Draw do
 
   end
 
+  context 'dsl overrides' do
+    subject(:draw)      {Squib::Args::Draw.new(custom_colors, {stroke_width: 0.0})}
+
+    it 'works when specified' do
+      draw.load!({}) # go right to defaults
+      expect(draw.stroke_width).to eq( [0.0] ) #ordinarily a non-zero according
+    end
+
+  end
+
   context 'validation' do
 
     it 'converts to Cairo options' do